Dreadfell help

[Red]

Diggers
32 Chambers (GMH Wyrm)
Demon Nest 1 (Major Demon)
Demon Nest 3 (Major Demon and Fire Wyrm)
Greater Crypt (GMH Wyrm)

According to the wiki, these are all the Greater Vaults that can generate monsters of a +30 level, with the kind of monster in parentheses. So, assuming the wiki is fully accurate, you could encounter a level 60+ spider in the Diggers Vault, assuming you yourself were level 30+.

[LordKarasuman]

Diggers could be it; honestly, my memory is the worst.